Monday, July 20, 2015

Baryonyx: Beast of the Week

This week we shall be checking out a dinosaur that seemed to have been specially adapted for getting its food from the water.  Enter Baryonyx walkeri!

Baryonyx was a meat-eating dinosaur that lived in what is now Southern England, Spain, and Portugal, during the Early Cretaceous Period, between 130 and 125 million years ago.  From snout to tail it measured about thirty one feet long. (Although paleontologists believe an older adult could have grown even larger.)  The genus name, Baryonyx, translates to "Heavy Nail/Claw" in reference to the first claw on each of its hands which were each almost ten inches long!  When alive, it would have coexisted with many other dinosaurs that are known from the area, including Eotyrannus, Mantellisaurus, and Iguanodon, to name just a few.

Baryonyx walkeri life reconstruction by Christopher DiPiazza.

Baryonyx belongs to the family, spinosauridae.  Spinosaurids were theropod dinosaurs which all had long, narrow snouts filled with pointed, cone-shaped teeth.  Spinosaurids also all had three fingers on each hand, with the first claw on each being much bigger than the others.  Even though the much more popular, Spinosaurus, was discovered first (and thus the family name is in its honor), Baryonyx was the first Spinosaurid in which paleontologists were able to identify these telltale morphological characteristics from.  Spinosaurus, on the other hand, was only known from very scant remains and was reconstructed as a general large theropod until relatively recently.  Since the discovery of Baryonyx in the 1980s, several more kinds spinosaurids have also been discovered.

Baryonyx skeletal mount on display at the London Museum of Natural History.

So what was the reason Baryonyx evolved such an interesting snout?  It is unlike most snouts seen on other large kinds of theropods, which tend to be much deeper.  The answer lies in the stomach contents of Baryonyx, which luckily, also fossilized!  Paleontologists were able to identify fossilized fish scales and bones inside where the stomach of Baryonyx once was.  This confirms that Baryonyx had a taste for seafood! (or  This makes sense given the long snout and the pointed teeth, which would have been ideal for snapping up and holding onto slippery aquatic prey.  Baryonyx's nostrils were also placed about midway up the snout, not at the tip, like in most theropods.  This would make sense if it was dipping its face in the water frequently.  The giant, hook-shaped claws of this dinosaur also may have played a role in fishing as well, by being able to grab anything that somehow managed to escape the jaws.  Also keep in mind that what is now Southern England, was once a vast network of swampy rivers and lakes during the Early Cretaceous, when Baryonyx lived there, where it would have had no problem finding plenty of fish to eat.  I can imagine Baryonyx when it was alive hunting in a humid Cretaceous wetland with the front of its snout submerged in shallow water, slightly ajar, as it stands motionless, waiting for prey to venture close enough.  It would stand still for so long that local fish would start to get used to the large dinosaur as just another part of their environment.  Then, when the time was right it would snap up an unlucky fish lightning fast, tossing its head back and swallowing it whole!

Baryonyx's digit 1 claw.

Baryonyx wasn't just a fish-eater, however.  There have also been chunks of Iguanodon bones found inside of it's skeleton, as well, proving that other dinosaurs weren't off the menu for this spinosaurid, either.  Whether or not Baryonyx killed the plant-eating dinosaurs itself, or scavenged them is still a mystery.  Baryonyx's jaws, although relatively narrow, were still more robust, and capable of sustaining more pressure than those of other, more specialized members of its family, like Spinosaurus.

That is all for this week!  As always, feel free to comment below or on our facebook page!


Charig, A. J.; Milner, A. C. (1997). "Baryonyx walkeri, a fish-eating dinosaur from the Wealden of Surrey". Bulletin of the Natural History Museum of London 53: 11–70.

Cuff, A. R.; Rayfield, E. J. (2013). Farke, Andrew A, ed. "Feeding Mechanics in Spinosaurid Theropods and Extant Crocodilians". PLoS ONE 8 (5): e65295.

Edwards, D. D. (1986). "Fossil Claw Unearths a New Family Tree". Science News 130 (23): 356. doi:10.2307/3970849. JSTOR 3970849.


  1. Uhh...baryonychines actually had less robust jaws than spinosaurines, despite the fact their legs were more generalized.

    1. Did you read the paper second on the list under references at the bottom of this post? Check it out. According to what they found out, Baryonyx jaws hold up better under stress than those of Spinosaurus. They tested them against a few kinds of crocodilians too. Legs had nothing to do with it.